To strengthen competitiveness of a future mobile network, the 3rd Generation Partnership Project (3GPP, The 3rd Generation Partnership Project) focuses on system architecture evolution (SAE, System Architecture Evolution) of multi-network convergence in next-stage major development. A user may access an evolved packet core network (Evolved Packet Core) by using either a 3GPP access system or a non-3GPP (non 3GPP) access system. The 3GPP access system is a general packet radio service GPRS system, a Universal Mobile Telephone System UMTS, an evolved system architecture SAE, or the like. The non-3GPP access system is a wireless local area network WLAN, a Worldwide Interoperability for Microwave Access WiMAX network, a Code Division Multiple Access CDMA or CDMA2000 system, or the like.
For example, with development of a mobile communications system, a mobile communications technology provides an increasingly higher transmission rate and increasingly higher service network load quality. Wireless Fidelity (Wireless-Fidelity, WiFi for short) of a wireless local area network (Wireless Local Area Network, WLAN for short) is a type of wireless local area network that uses IEEE 802.11 family of standards. Because of a high transmission rate and convenient network deployment, Wireless Fidelity currently has become one of the most widely used WLANs. A user equipment (User Equipment, UE for short), such as a smartphone, may access a WLAN by using an access point (Access Point, AP) of the wireless local area network. In addition, the UE may also access the 3GPP by using a base station, for example, the UE accesses Long Term Evolution (Long Term Evolution, LTE) by using an evolved NodeB (evolved Node B, eNodeB for short). The development of mobile communications technologies enriches communication functions and capabilities of a UE and further popularizes the UE. However, popularization of the UE causes increasing load pressure of a WLAN, which results in a problem that due to capacity saturation, the WLAN cannot support normal communication of the UE.
Currently, there is a lack of an effective mechanism that ensures proper migration of a UE between WiFi and LTE to support normal communication of the UE.